New Way to Investigate Crime: A DNA Test for Hair Color

Never mind what the sleuths on CSI would have you believe, finding DNA at the scene of a crime can sometimes be a dead end. Your genome may readily reveal your susceptibility to certain diseases or even the consistency of your ear wax, but it’s notoriously bad at saying much about your key physical characteristics. However, researchers from Erasmus Medical Center in Rotterdam in the Netherlands and colleagues in Poland have isolated 13 genetic markers in 11 different genes that may predict one key feature — hair color — with remarkable accuracy.(More on TIME.com:Photos: See the most unforgettable images from 2010)

While the entire human genome has been mapped, the precise interplay of genes is another matter. Just like knowing the age and gender of everyone in a room does not tell you much about how all of those people will get along, so too is a mere listing of genes limited in what it reveals about how they work together to shape the larger organism. This is particularly so in the case of physical appearance, with the exception of eye color – a trait that has been traced to the interaction of 15 well-understood genes.

Now the Dutch-Polish team has brought the same clarity to hair color, developing a test that is 90% accurate in determining if someone is red-headed, nearly as precise for black hair and works just over 80% of the time for people with blond or brown hair. What’s more, the test can distinguish between varied shades of each color — dirty blond versus golden-colored, for example. (More on Time.com:See the top 10 medical breakthroughs of 2010)

“This type of objective information can be used to refine the description of an unknown but wanted person,” said Prof. Ate Kloosterman of the Department of Human Biological Traces at the Netherlands Forensic Institute (NFI). “This new development results in an important expansion of the future DNA tool kit used by forensic investigators to track down unknown offenders.”

Of course, the bad guys have a very powerful tool in their kit too: hair dye — proving once again that even a very high-tech thrust can sometimes be beaten by a low-tech parry.